Handheld Refractometers measure how light bends through a liquid sample to report sugar concentration, salinity or refractive index on a digital display. Brix models cover 0.0 to 32.0% and 0.0 to 53.0% with ±0.2% accuracy, salinity models read seawater and brine strength, and a dedicated model reports refractive index. Automatic temperature compensation from 10 to 75 °C on Brix and salinity models corrects readings taken in orchards, kitchens and plants. A 0.3 ml sample covers the glass prism, and zinc alloy bodies with touch-button unit switching suit daily handling. Typical uses include fruit ripeness checks, juice and beverage production, aquaculture salinity checks and food QC.